The 22-year-old Tuiasosopo said he built the online persona of Lennay Kekua, a nonexistent woman who Te'o said he fell for without ever meeting in person and later believed to have died of leukemia.
Tuiasosopo said he felt Kekua was a part of him, and grew feelings and emotions for Te'o that he could not control. He acknowledged that the hoax was cruel, but said it was never intended as a joke and that he got no financial gain from it.
"I pretty much had this escape of Lennay and this was where my heart had pretty much invested, not just time, but all of my energy went into this," he said.
"As twisted and confusing as it may be, yeah, I cared for this person," he said, referring to Te'o. "I did all that I could to help this person become a better person, even though I wasn't getting nothing out of it."
When the ruse was reported by Deadspin.com on Jan. 16, the report raised the questions about whether Te'o was involved. The story about how the All-American played through pain learning about the deaths of his girlfriend and grandmother on the same day led to an outpouring of support from Notre Dame fans. It became the backdrop to the Fighting Irish's undefeated regular season and run to the BCS championship, where they lost to Alabama.
Tuiasosopo said Te'o knew nothing of the hoax, and doesn't believe he ever suspected Kekua wasn't real.
"He had no involvement," Tuiasosopo said. "He did not know anything."
Te'o won seven national awards for his play and was runner-up for the Heisman Trophy. He has denied any involvement from the beginning, and Notre Dame said an investigation of the player's claims backed up his story.
But Tuiasosopo said he felt Te'o became a better person as a result of the relationship.
"If you really look at all his interviews, he felt that," he said. "When he was under the understanding that he lost her, he realized all the good that Lennay had done for him."
Through a spokesman, the Te'o family declined comment.
Tuisasosopo said he decided to confess to Te'o earlier this month as the hoax was unraveling because he felt he could not go any further with his own life until the truth was out.
"You've heard of recovering drug addicts? It takes a lot of courage to stand and say that," he said "To recover from homosexuality and this type of thing. Not only that, coming back to your real life, as hard as a task as that is I'm going to do all that I can to live right."
McGraw said that statement bothered him.
"I hope it's a pressure you don't put on yourself," he said.
Tuiasosopo said he killed the Kekua character on the day in September Te'o learned his grandmother died, following an argument with Te'o.
The football star had told Kekua he didn't need her, Tuiasosopo said.
"It hurt me," he said. "It hit me like a brick wall. I was like, 'Whoa, I've given so much into this. And I realized right then in that moment, that I poured so much into Lennay, that I myself was getting nothing, and look what I was left with."
Te'o said he first learned that something was amiss when Keuka called him on Dec. 6, and told him she had faked her death.
He told his parents about what had happened while home for Christmas break and called Notre Dame coaches on Dec. 26 to let them know. Notre Dame officials said that they interviewed Te'o and retained Stroz Friedberg, a New York computer forensics firm, to investigate the case. They learned on Jan. 3 that there were no records indicating Lennay Kekua existed.
Tuiasosopo said he was the voice of Kekua but initially refused to recreate it when pressed by McGraw. He eventually agreed to do the voice behind a privacy screen, something McGraw promised to show during part two of the interview on Friday.